Guillermo del Toro’s adaptation of “The Hobbit” will have some familiar faces. “Lord of the Rings” trilogy actors Andy Serkis (Gollum), Ian McKellen (Gandalf) and Hugo Weaving (Elrond) will all reprise their roles, the director revealed on BBC Radio’s Simon Mayo program. “The Hobbit,” based on the book by J.R.R. Tolkien, is set before the events of the author’s “LOTR” series, and follows Frodo Baggins’ uncle, Bilbo, and his adventures in acquiring the one Ring. Del Toro intends on splitting the book into two films, and revealed on the program that Gandalf’s abrupt departure from Bilbo and the dwarves’ quest against the dragon Smaug – not narrated in the novel – will appear on screen as a means of further linking the film to Peter Jackson’s “Lord of the Rings” movies. “There is a whole other chapter, so to speak, which is the comings and going of Gandalf which are dealt with,” del Toro said. “People that know the lore know that Gandalf was delayed with a crisis… with a character that is very shady called the Necromancer that proves to be Sauron.” In the “Lord of the Rings” trilogy, Sauron – a rival wizard to Gandalf – was played by Sala Baker. The director didn’t say if he would appear in the upcoming films. The first installment of “The Hobbit” is due in December 2011.